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1.发明授权公开(公告)号：US10334694B2
公开(公告)日：2019-06-25
申请号：US16151718
申请日：2018-10-04
Applicant: SEIKO EPSON CORPORATION
Inventor： Norikazu Tsukahara , Atsushi Yamada , Kei Ishimaru
Abstract: A light emission control circuit includes a drive circuit that generates a first control signal in order to control a first switching element, and a switching control circuit that generates a second control signal in order to control a second switching element. The switching control circuit maintains the second control signal in an inactivation state in a period in which the first control signal is inactivated in a case where an ON duty ratio of the first control signal is equal to or more than a predetermined value, and maintains the second control signal in an activation state in a part of the period in which the first control signal is inactivated in a case where the ON duty ratio of the first control signal is less than the predetermined value.
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公开(公告)号：US11324100B2
公开(公告)日：2022-05-03
申请号：US17004633
申请日：2020-08-27
Applicant: SEIKO EPSON CORPORATION
Inventor： Kei Ishimaru , Atsushi Yamada
Abstract: Provided is a light source apparatus including semiconductor light sources and a current detection resistor connected in series, a power source circuit that allows current to flow thereto, a current detection circuit that detects current flowing to the current detection resistor and outputs a current detection signal, a control circuit that controls the power source circuit such that a voltage of the current detection signal approaches a target value, a bypass circuit connected in parallel to the semiconductor light sources, and including a clamp element having a clamp voltage higher than a maximum voltage during operation of the semiconductor light sources and a bypass resistor connected in series to the clamp element, and allowing current to flow when an open fault occurs in the semiconductor light sources, and detection circuits that respectively detect an open fault in the semiconductor light sources based on an end-to-end voltage of the bypass resistors.
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3.发明授权公开(公告)号：US10036945B2
公开(公告)日：2018-07-31
申请号：US15840385
申请日：2017-12-13
Applicant: SEIKO EPSON CORPORATION
Inventor： Atsushi Yamada , Norikazu Tsukahara , Kei Ishimaru
CPC classification number: G03B21/2053 , G03B21/2033 , H04N9/3155 , H04N9/3182 , H05B33/0815 , H05B33/0818 , H05B33/0851 , H05B37/0227
Abstract: This light emission control circuit controls a first switching element for controlling a current that flows to a light-emitting element connected between a first node and one end of an inductor, and a second switching element for controlling a current that flows from the other end of the inductor to a second node. The light emission control circuit has a driving circuit that generates a first control signal for controlling the first switching element, and a switching control circuit that generate a second control signal for controlling the second switching element, and deactivates the second control signal in order to bring the second switching element into an off-state, during a period during which the first switching element is in an off-state.
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Patent Agency Ranking
公开(公告)号：US11761991B2
公开(公告)日：2023-09-19
申请号：US17706924
申请日：2022-03-29
Applicant: Seiko Epson Corporation
Inventor： Toshimichi Yamada , Kei Ishimaru
CPC classification number: G01R19/0023 , G01R1/203
Abstract: A current detection circuit includes an operational amplifier, a current sense amplifier including a first resistor and a second resistor, and a level shifter. The first resistor is provided between one end of a shunt resistor and a first input node of the operational amplifier. The second resistor is provided between the other end of the shunt resistor and a second input node of the operational amplifier. The level shifter controls voltages of the first input node and the second input node by controlling, according to a voltage at the one end of the shunt resistor, currents supplied to the first input node and the second input node.
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公开(公告)号：US11632831B2
公开(公告)日：2023-04-18
申请号：US17582362
申请日：2022-01-24
Applicant: Seiko Epson Corporation
Inventor： Kei Ishimaru
IPC: H05B45/10 , H05B45/3725 , H05B45/325
Abstract: The integrated circuit device includes a drive circuit and a regulator. The drive circuit outputs a drive signal to a switching element. A source power supply voltage the same in potential as a source voltage of a transistor as the switching element is input to the regulator, and the regulator generates a gate power supply voltage based on the source power supply voltage. The drive circuit has a level shifter for level-shifting a PWM signal based on the gate power supply voltage and the source power supply voltage. The drive circuit outputs the drive signal based on an output signal of the level shifter to the gate of the transistor.
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公开(公告)号：US12224115B2
公开(公告)日：2025-02-11
申请号：US18170915
申请日：2023-02-17
Applicant: SEIKO EPSON CORPORATION
Inventor： Kei Ishimaru , Yoshihiko Nimura
IPC: H01F7/06 , H03F3/45 , H03K19/0175
Abstract: A current sense amplifier circuit of a circuit device includes: an operational amplifier; a first resistor provided between one end of a shunt resistor and a first node, a first switch provided between the first node and a first input node, a second resistor provided between another end of the shunt resistor and a second node, a second switch provided between the second node and a second input node, a third resistor provided between a constant voltage node and the third node, a third switch provided between the third node and the first input node, a fourth resistor provided between the constant voltage node and a fourth node, and a fourth switch provided between the fourth node and the second input node.
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公开(公告)号：US11749684B2
公开(公告)日：2023-09-05
申请号：US16943173
申请日：2020-07-30
Applicant: Seiko Epson Corporation
Inventor： Kei Ishimaru , Atsushi Yamada
IPC: H01L27/092 , H04N9/31 , G09G3/32 , H01L27/06 , H05B45/30 , H01L29/06 , H10B10/00 , H01L29/861 , G09G3/00 , H01L29/78
CPC classification number: H01L27/0928 , G09G3/32 , H01L27/06 , H01L29/0611 , H04N9/3123 , H04N9/3155 , H05B45/30 , H10B10/18 , G09G3/001 , G09G2330/12 , H01L29/78 , H01L29/8611
Abstract: A circuit device includes an N-type well on a P-type substrate, a P-type well provided in the N-type well, a circuit element provided in the P-type well, a P-type well provided in an N-type well, and a circuit element provided in the P-type well. A ground power supply voltage is supplied to a P-type well. A power supply voltage different from the ground power supply voltage is supplied to a P-type well. The ground power supply voltage or a first potential that is greater than or equal to the potential of the ground power supply voltage and less than the potential of a high potential-side power supply voltage is supplied to an N-type well.
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8.发明授权公开(公告)号：US10795251B2
公开(公告)日：2020-10-06
申请号：US16794353
申请日：2020-02-19
Applicant: SEIKO EPSON CORPORATION
Inventor： Kei Ishimaru
Abstract: The light emission control device includes a PWM terminal to which a PWM signal is input, a first drive circuit for outputting a first control signal, a second drive circuit for outputting a second control signal, and a mode judgment circuit. The first control signal sets the first switching element to an ON state when the PWM signal is in an active state, and sets the first switching element to an OFF state when the PWM signal is in an inactive state. The second control signal controls an ON/OFF state of the second switching element when the PWM signal is in the active state. The mode judgment circuit judges between a PWM dimming mode and an analog dimming mode based on the PWM signal.
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